Metal choice and welding.

[JetSet]

Hello.

I am looking to build a lockwood, and from what i have read, i will need some 0.8mm thich '321' grade stainless steel sheet.

I now have access to an arc welder, and have loads of welding rods which i think are for mild steel. Would these suffice, or will I need to buy some rods designed for stainless too?

Thanks for any info.

[Viv]

Hello.

I am looking to build a lockwood, and from what i have read, i will need some 0.8mm thich '321' grade stainless steel sheet.

I now have access to an arc welder, and have loads of welding rods which i think are for mild steel. Would these suffice, or will I need to buy some rods designed for stainless too?

Thanks for any info.

we can supply 321 grade sheet but you are a bit far away for us to ship it to you:-)

We can however supply a complete laser cut kit of the parts for a Lockwood engine in 321 grade stainless steel, this is all the parts cut to profile so you just need to weld them up after rolling, supplied in a flat pack for shipping.

You will need a TIG welder for 321 grade and 347 filler wire, a stick (arc) welder will not work I am afriad.

I have just found a source for 321 grade 180 degree bends, I am trying to get these made as J leg bends so it will run from the combustion chamber to the exhaust in one peace, I will post a price for these soon.

Visit our web site for details

Viv

[JetSet]

It cant be arc welded?? That is a pain!! It has taken ages for me to get hold of that, hehe :-)

Would it be possible to use a MIG? I think thats the only other thing I will be able to get my hands on for the time being :oops:

[Viv]

It cant be arc welded?? That is a pain!! It has taken ages for me to get hold of that, hehe :-)

Would it be possible to use a MIG? I think thats the only other thing I will be able to get my hands on for the time being :oops:

It can be MIGed but the wire is pretty expensive I found when I lived in the UK, contact wells welding supplies in Oxford, he is the phone book and an onest guy to deal with for welding stuff.

The industry pretty much uses TIG for this kind of wleding job.

Viv

[Dave]

After spending the afternoon trying to weld stainless with a MIG welder I can tell you that TIG is the way to go. It can be done with MIG, but the process is tedious and results in some UGLY welds. From a strength prospective, I am sure the welds I did today are also far from ideal. Properly built jigs, back purging and using Solar Flux would probably help, but there just appears to be no substitute for a steady hand with TIG when it comes to critical operations and stainless.
Dave

[NanoSoft]

I MIG weld all my jets. The welds may not be perfect but they are by no means ugly. It just takes a lot of pratice and patience to get used to it. Once you get the technique down its a piece of cake.

Nanosoft

[Dave]

Nanosoft
Practice will definitely help, but I also get the feeling that the quality of the welder (both human and machine) plays a part in the equation. In my case neither is up to snuff.
Dave

[ed knesl]

Any engine that should last, must be built of stainless steel tubing.
It can be effectively welded by TIG only with back shielding by copper strips, or back purging with argon gas. Such procedure is time consuming and expensive.
Thin gages as 24 and 26 are rather difficult to weld and heat distortion is also a problem. Many of you do not have expensive TIG aparatus anyway.

There is a light at the end of the tunnel !

The answer is SPOT WELDING, which is extremely easy to use, no need for gas, filler rods and is very very cheap. Welds look great, no basic metal distortion and they are strong, since each weld is under shear stress only, because of overlaps.

I have demonstrated such engine on PJ Meet early this month.
After several quite long runs, TIG cross welds have shown some fatigue,
and base metal cracked around spark plug. ( Heat and vibrations )
All long spot welded seams dit not show any sign of overstress.

Currently I am finishing new engine, completely spot welded, with only minor sections TIG welded. Everything is perfectly round, straight and
clean.

edk

[Mike Everman]

I can't wait to see!

[evildrome]

Hi Ed,

I also have been considering spot welding for very thin stainless.

What equipment are you using ?

Thanks,

Wilson.

[Fricke]

[quote="JetSet"]It cant be arc welded?? That is a pain!! It has taken ages for me to get hold of that, hehe :-)

Would it be possible to use a MIG? I think thats the only other thing I will be able to get my hands on for the time being :oops:[/quote]

There are TIG-attachments to ARC-welders... Works great... As it is stainless steel you just touch the work with the tungsten electrode to strike an arc, and wels as usual... easy...

[Fricke]

The answer is SPOT WELDING, which is extremely easy to use, no need for gas, filler rods and is very very cheap. Welds look great, no basic metal distortion and they are strong, since each weld is under shear stress only, because of overlaps.

edk

Do You spotweld the whole seam or "normal" spotwelding spots?

[ed knesl]

The answer is SPOT WELDING, which is extremely easy to use, no need for gas, filler rods and is very very cheap. Welds look great, no basic metal distortion and they are strong, since each weld is under shear stress only, because of overlaps.

edk

Do You spotweld the whole seam or "normal" spotwelding spots?

Long seams are spotwelded ~1/2 " o.c. , cross sections ~ 1/4 in o.c.
Harbor Freight Tools sells two kinds. 110 and 220 volts, cost $140 approx.

edk.

[Mark]

I have been getting the Harbor Freight catalogs for several years. Just last week I went to one of their new stores right here in Pensacola. The Chinese are taking over. Some stuff is junk, but other stuff is far cheaper than any other store.
If you are like me, I glance through every catalog they mail me about every two weeks it seems, I don't know why, not too much changes, guess I just like to look at tools and stuff for ideas.
Mark

[Mark]

Interesting little fact.
http://fcr.iop.org/articles/features/2/4/3
Mark